Of course the emacs community welcomes new functionality.
There is already cua-mode.

cua-mode and viper-mode are two examples of customizations that are
extremely good. I use them both.

I believe emacs is such a
thing that if you believe your "modernized-mode" is good,
you can release it as a elisp package and put it on the
wiki.

If you look into the details of the code you will find that it is often
not that easy. Making cua-mode and viper-mode good citizens in Emacs has
required quite a lot of efforts to make room for them.

Smaller, not that complicated packages (or perhaps rather packages that
does not interfer that much with other parts) can be created outside of
Emacs.

Larger efforts is very hard to do outside - if no one has been smart
enough to offer very good and flexible support inside Emacs. Some people
are able to work around those difficulties, but it looks very difficult
to me (mostly thinking about CEDET).